Daniel sullivan



(No Model.)

- D. SULLIVAN.

SAFETY ATTACHMENT FOR BOILERS. No. 275,091. Patented Apr. 3, 1883. 5.1.

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UNITED STATES PATENT FFICE.

DANIEL SULLIVAN, OF LINCOLN, RHODE ISLAND.

SAFETY ATTACHMENT FOR BOILERS.

SPECIFICATION forming part of Letters Patent No. 275,091, dated April 3,1883.

Application filed May 9, 1882.

To all whom it may concern:

Be it known that I, DANIEL SULLIVAN, of the town of Lincoln, in thecounty of Providence and State of Rhode Island, haveinvented certain newand useful Improvementsin Steam Generators and Boilers; and I do herebydeclare that the following, taken in connection with the drawings whichaccompany and form part of this specification, is a description ofmyinvention sufficient to enable those skilled in the art to practiceit.

This invention relates to safety attachments for steam generators andboilers; and it consists of certain novel devices,hereinatter more fullydescribed, which become important adjuncts to the boiler, and aredesigned to supplement the safety-valve in case the latter should failin its proper functions.

To those skilled in the art it is well known that the principal causeassigned for boiler explosions, assuming that the material andworkmanship are of good quality, is overpressure. Overpressure may beinduced by the safety-valve being overweighted, by its sticking on itsseat, or by the inadequate size of the communication between the boilerand valve, and all these causes may be attributed either to ignorance orto 'a want of skill in the care and management of the boiler.

The object of this invention is to provide certain mechanical meanswhereby the safety of the boiler shall be secured against a worth lesssteam-gage and safety-valve and the ignorance or carelessness oftheperson in charge. It is evident that if an explosion occurs the boilerwill give way at that point in the steam area which is weakest; or, inother words, the resistance of a boiler to steam-pressure must bemeasured by its weakest point. My invention seeks to provide such awcakpoint, which consists of a metallic plate of reduced w0rkingstrength,located outside the boiler proper, but connected thereto bymeans of a flue and a perforated pipe extending longitudinally in thesteam-area within the boiler.

In the drawings, Figure 1 represents an ordiuary steam-boiler with aportion of the shell broken away, theperforated pipe in the steamroom, avertical section of the flues, globes,

(No model.)

globe horizontally, partly in section; and Fig. 3 represents aperforated metal plate, partly in section, that bisects the smallerglobe.

Similar letters of reference indicate corresponding parts.

Ais a perforated pipe, located in the steamspace and longitudinally ofthe boiler. The perforations are made in the top and extend along theentirelength.

E is a flue, that connects the perforated pipe with the globe 1),through which the steam is conducted into the lower half of said globe.The flue'E is made up of a short pipe riveted to the boiler, havingcommunication with the perforated pipe A and the nozzle-extension of theglobe-hemisphere. The steam is arrested in the larger globe by the plateB, which bisects said globe horizontally and constitutes the weak pointof the boiler, and is that part in which the collapse takes place shouldthe steam-pressure exceed the tensile pressure of said plate. Theresistance of the plate B to the steam-pressure is intended to besomewhat greater than the statical pressure in the boilerthat is, thepressure which would be required to raise a perfectly-workingsafetyvalve from its seat-and considerably less than the estimatedworking strength of the boiler.

The globe D, for convenience of construction, is made in twohemispheres, with flanges formed at the line of contact, when puttogether, to make steam-tight seams, and each hemisphere terminates inflanged nozzles g. The flanges on the nozzles afford suitable means toreceive bolts to connect the parts.

The smaller globe O is bisected with a perforated plate, H, and is partof the detail of my invention. This globe is formed by enlarging thenozzleg ofthe upper hemisphere ot'the globe D for the lower half, andthe lower part of the neck of the valve above for the upper halfot'saidglobe. The perforations in the plate within the globe O serve as outletsfor the steam after the collapse of the plate 13. Above the globe O, andattached to it, is an ordinary valve, V, with handle K, by which it maybe opened and closed at pleasure. The valve should be kept open andlocked to avoid any contingency of its being closed, because it affordsthe only exit for the steam, which relieves the boiler fromoverpressure. The handle K places the valve under control of theattendant, which should be closed to confine the steam when reduced to asafe working load.

The pipe A is perforated the entire length, that the steam and water inthe boiler may not rush through in a body, and that all parts of theboiler shall berelieved of pressure simultaneously after the collapse ofthe plate 13. The perforated plateH breaks the force of the steam in itspassage through the valve. The plate B, bisecting the larger globe D, isa circular piece of homogeneous metal (steel pre ferred) of any giventensile strength, which will be determined by the load the boiler isintended to carry. These plates are made of different thicknesses, whichwill be capable of resisting different degrees of pressure, so that whenthe limit of strength is known or determined on it will be necessaryonly to select the plate that corresponds to the required resistance.

The method of applying the safety attachment is as follows: The steamrises from the boiler and passes through the perforations of the pipe A,through the flue E into the lower half of the globe D, and fills thespace below the plate B,exerting the same pressure on said plate as onthe other parts of the boiler. If the safety-valve should fail torelease the steam when the boiler is overloaded-that is, sustaining apressure from the steam in excess of what should raise the valve in anormal eonditionthen itisintended that the plate should collapse orburst, and the steam would pass out through the valve V, which affordsthe relief that the imperfect safety-valve failed to provide. At theproper time the valve can be closed by the handle K, and the boiler maybe then used as before, or until a new plate is substituted for the onethat collapsed.

The chambers (l and D, which I have represented aud designated as globesmay be of other forms; but the sphericalform is preferable, because itcan be made cheaper, better 5 joints can be obtained, and less spacewill be required.

While the globe O, perforated plate H, and the valve V are importantfactors to the perfect working of my invention, I do not regard theseelements indispensable to the organization. If these features wereomitted, the outlet at the top of the globe D should be smaller thanwhen these appliances are put to use. The same general result would beattained if the outlet of the globe D were covered with a perforatedplate, properly secured thereto. A still better result would follow by avalve like V, attached to the globe D; but to obtain the best results Iam persuaded that all theelements as described and illustrated should beemployed.

I am aware that bursting-plates have been used before my invention; butwith these no provision was made for escape of the steam beyond thewalls of the small chamber in which the bursting-plate was located. Ofnecessity the relief thus afforded could be but temporary, and must bemeasured by the capacity of such chamber.

Having thus described my invention, I claim as new and desire to secureby Letters Patent 1. In combination, substantially as specified, asteam-boiler, perforated pipe located in the steam-space,bursting-plate, chamber D, and a suitable device, substantially asdescribed,for releasing the steam from the boiler.

2. The combination of a steam-boiler and a safety attachment, consistingof a perforated pipe located in the steam-space of the boiler, a globebisected horizontally with a homogeneous metal plate calculated topossess less resistance to steam-pressure than the boiler to which it isattached, a smaller globe bisected by a perforated plate and avalve-outlet for the steam, substantially as specified.

3. A perforated pipe located in the steamspace, for the purposespecified, substantially as described and illustrated.

DANIEL SULLIVAN.

Witnesses:

'H. BJUARPENTER,

E. L. FREEMAN.

